Artificial leg.



J. T. APGAR.

ARTIFICIAL LEG. Y APPLICATION FILED DEG. 30, 1912. 1,082,255. PatentedDe0.23,1913.

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Y* J. T. APGAR.

ARTIFICIAL LEG.

APPLIGATION FILED 13110.30, 1912.

1,082,255. Patented Dec. 23, 1913.

3 SHEETS-SHEET 2. 0 @5' l l I i I J. T. APGAR.

ARTIFGIAL LEG.

APPLICATION FILED 1320.30, 1912.

1,082,255. Patented Dec. 23, 1913.

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llNllTEiD STATES PATENT FFCF.

JOHN T. APGAR, OF NEW YORK, N, Y.

ARTIFICIAL LEG.

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Application led December 30, 1912.

To all Lc/1.0m it may concern Re it known that I, Jol-IN T. APGAR, acitizen of the United States of America, resid ing' at New York city,borough of Manhattan, county and State of New York, have inventedcertain new and useful Improvements in Artificial Legs, of which thefollowing` is a full, clear, and eXact description.

'lhis invention relates to an improvement in artificial legs andpertains more particularly to novel means for yieldably support` ing thesocket, and for adjusting or regulating' the tension of the yieldablesupportinn1 means.

Other features of my improvement will be hereinafter set forth andclaimed.

l will now proceed to describe my invention in detail, the novelfeatures of which I will point out in the appended claims, ref erencebeine' had to the accompanying drawings. forming' part hereof, wherein:

Figure l is a side elevation of an artificial leg' embodying myimprovements; Fig. 2 is a rear elevation of the lower member thereof;Fig. 3 is an enlarged vertical sectional view of the upper portion ofthe lower leg-member; Fig. 4l is a cross-sectional plan view thereof.the section being taken on a line t-t in Fig. 3; Fie'. 5 is a verticalsectional view of a modification of the device illustrated in Fig. 3;Fig. 6 is a cross-sectional plan view thereof. the section being takenon a line 6-6 in Fig. 5; Fig'. 7 is a vertical sectional view of myimproved ankle-block. and portion of the foot-member; Fig. 8 is a bottomplan view of the ankle-block; 9 is a rear elevation, partly in section,of the ankle-block; Fig. 10 is a diagrammatic side elevation,illustratinp,` the ankle-block in its rearward position. Fig'. 1l is amodified form of ankleblock, and Fig. l2 is a modified form of closurefor the bottom of the stump socket.

In the drawings the numeral l indicates the lower member of anartificial leg, while 2 indicates the upper member which is laced to thestump above the knee, the members 1 and 2 being' pivotally connected at3. Thus far the leerr constitutes a well-known structure provided withan ankle-bloek l and attached foot-member 5. It is usual to provide thisform of artificial leg with a stump socket 6, which is designed tosupport for instance the stump of a lee' which has been amputated belowthe knee. The stump which is carried by the socket 6 Specification ofLetters Patent.

Patented Dec.. 23, i913. semi no. 739,238.

should be rendered lit to support its proportionate part of the weightof the body, but owing' to the fact that these Sockets are not desicncdto yield, so as to take considerable strain ed the stump and alsocushion the thrust thereupon. any great amount of weicht cannotI beplaced upon the stump, and hence the other leef has to take the greaterpart of the weight. llhile walking, the artificial member is thrownforward by the remaining' portion of the amputated member. but it is notthrown forwardly in a substantially straight line but rather to one sidein order that the weight of the body will not be imposed directly uponthe stump in a vertical direction, when the weight of the body isshifted to permit the normal les, to be thrown forward. li ence thelimp. When disposed at an angle. the stump takes the weight, or at leastthe greater part of it on the inside thereof and not upon the end of thestump which is somewhat tender.

By referring): to Fig. 3 it will be seen that the socket 6 is notsecured to the member l, but is free to move lone'itudinally thereof7 sothat when the weight. of the body is imposed upon the stump, the socketwill yield or move downwardly. thereby permitting the stump to graduallyabsorb the weight or accommodate itself to the imposed strain. To permitthe socket to yield. l provide a cushioning' or yielding' element, inthis instance a spring' 7 which is fitted at the upper end thereof. in apocket 8 in the bottom 9 of the socket (i. The lower end of the spring'or cushioning' element 7 is located in the threaded bore of a saddle l0and rests upon. an adjustable block ll provided with a slot l2 hv whichthe said block can be adiusted longitudinallT of the bore of the saddle10, in order that the tension of the spring; 7 can he altered oradiusted to suit the weight imposed upon the stump socket supportedthereby. Bv means of the adiustable support for the sprinsr the tensionthereof can be altered to suit the weight of the wearer of the lee'.Furthermore. the adiustability of the yielding support for the socketmakes it possible to alter the cushioninrr action thereof. or rather thedegree of the cushioninfr action. should the wearer of the lee' @fain orlose weight.. The saddle l0 is provided with fia-mees 13 which areriveted to the leg member l.

The wearer of the leo; can easily determine whether the cushioning`medium is too stiff or too free for his weight. It would be almostimpossible to temper a spring to produce a cushioning effect to meet allrequirements; hence it is highly essential that some means be providedfor adjusting the tension of the cushioning element. To adapt the socketG to be tightly secured to the legstump, I partly split or sever thesame as at 14 and provide a turnbuckle 15 which engages brackets 16 onthe socket. l/Vhen the stump is placed in the pocket, the turnbuckle 15can be manipulated to draw the socket tightly around the stump. An apron17 is provided to cover the gap 14 so that the flesh will not protrudethereinto when the socket is tightened. It may here be stated that inpractice the socket 6 fits the leg member 1 more closely than hereinillustrated.

I have not and will not describe the construction of the leg elements,nor the sockets, excepting that rawhide and leather will be used, as isusual.

A further feature of my improvement rcsides in alining 18 for the lowerleg member and a covering 19 for the socket 6 to prevent the squeakingof the two members when in action. I prefer to make the elements 18 and19 outI of buckskin or some other similar material which when rubbedtogether will not squeak.

Fig. 5 illustrates a modified lforni of resilient support for the socket6, and comprises a tubular member 20 carried by the bottom member 9 ofthe socket. The member 20 retains a spring 21, the lower end of whichrests upon an adjustable post 22 which in turn is carried by a threadedplate 23 the said plate being carried by a flange 24, which is securedto the leg member 1. The adjustment of the tension of the spring 21 willbe apparent.

A further advantageous feature of my in vention consists of theankle-block 4. (See Figs. 7 to 9 inclusive.) Ihe chief object of thisfeature of my improved leg is to provide an ankle-block which will bemore serviceable than-those now in use; and to render the block moreserviceable, I have improved the bearing portion of the block, or thatpart of the block which movably supports the device that holds the blockin position on the foot port-ion of the leg.

Referring to Figs. 7, 8 and 9, the ankleblock 4 is provided with atrunnion-member 25 which is provided with circumferential ribs 26, whichin turn enter curved grooves in the foot portion 5 in the manner usualin artiiicial leg construction. The ribs 26 prevent the side lashing ofthe block on the foot-portion. The foot-portion 5 is provided withcurved recesses 27 which rotatably support the trunnion 25. 'Ihe ankle-Vblock is held in position on the footl` the trunnion 25 engaging therecess 27, by a journal 28 and bolt 29. To decrease the wear of themetal, I cover the journal 28 with a leather sleeve 30. The spindle 28,and cover 30 therefor, extend the full length of the bearing provided bythe bore 32 of the trunnion 25. rEhe trunnion 25 is provided with anopening` 31 through which the bolt 29 passes and within which the saidbolt can work. 'Io gain the results desired, I cast or otherwise formthe trunnion 25 integral with the block 4, the said block beingpreferably made out of aluminum. It is usual to secure these trunnionsto the ankle-blocks by bolts which pass through the trunnion, hence itis not possible to rotatably support a journal, such as 28, throughoutthe full length of the trunnion, and consequently a good bearing surfacecannot be obtained, so that these parts soon wear out. rIhe objectI ofthe comparatively extensive bearing surface, provided by the abovedescribed construction is to adapt these parts to wear longer than theyotherwise would.

A further feature of the ankle-block is the mounting of the heel spring33 which is carried by the threaded tube 34. The tube 34 is screwedint-o the block 4 and is held against movement by a set-screw 35. Thelower end of the spring 33 rests in a recess 36 in the foot portion 5.The tube 34 supports the spring, rendering it compressible andpreventing it from buckling. One of the chief annoyances to a wearer ofan artificial leg is the fact that a shoe, at the rear thereof, willcrowd in the space 37 between the ankle-block and foot portion when theankle portion is rocked backward, while a person is walking. To preventthis I provide the resilient member 38, which in this instance consistsof a spring. rIhe member 38 is fixed to the foot portion 5 at'39, theupper end thereof being slidably retained in a groove 40 in theankle-block. IVhen the ankle-block is rocked backwardly (see Fig. 10)the spring 38 will yield and move backwardly, thereby offeringcomparatively little or no resistance to the action of the ankleblock.The presence of the spring 38 prevents the shoe from crowding into thespace 37. Vhen the shoe crowds into the space 37 it hinders the actionofthe ankle-block.

Instead of providing the bottom of the stump socket 6 with the block 9,for the spring 7 to seat in, I may use a metal member 41 see Fig. 12\which carries an annular `flange 42 to provide a pocket 43 for thereception of the spring 7. rIhe member 41 also carries a flange 44 towhich the socket 6V is riveted. In lieu of the threaded tube 34, for theankle-block 4, I may provide the said block with a core 45 (Fig. Il) toreceive the spring 33, the said core being surrounded by an annularliange 46.

By referring to Figs. 1 and 2, it will be seen that the stump-socket 6extends above the edge of the leg member 1, it being kept in suchposition by the tension device or cushion. The stump socket will beconstructed so as to preventthe downward movement thereof from causingthe upper edge of the socket 6 to go below the top edge of the legmember 1, the object being to prevent the stump socket from ever movingdownwardly enough to make the articial member shorter than the naturalleg, thereby preventing a limp. In other words, the top edge of thestump 6 is slightly larger in diameter than the inside of the leg member1; hence the stump-socket can never go below the top edge of the legmember 1.

Having now described my invention, what I claim and desire to secure byLetters Patent is:

1. The combination of an artificial legmember, a stump socket carriedthereby and normally free from the sides of the leg, a support carriedby said leg-member, a spring interposed between said support and saidstump socket, said spring being located centrally of the base of thestump socket and said support, and means to regulate the tension of saidspring.

2. The combination of an artificial legmember, a stump socket carriedthereby, a threaded support carried by said leg member, a threaded blockengaging the threads of the said support, a spring carried by saidthreaded block, said spring bearing against the lower end of the stumpsocket and located centrally thereof.

3. In combination with an ankle-block and a foot-portion movably securedthereto, a threaded tube screwed into said ankle-block, means forlocking said threaded tube, and a spring carried by said tube, saidfoot-portion being provided with a socket adapted to receive the lowerend of said spring.

Signed at New York city, N. Y., this 27th day of December, 1912.

JOHN T. APGAR. lVitnesses:

EDWARD A. JARvIs, MAURICE BLOCH.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents.

Washington, D. G.

